[SOLVED] Scrollarea doesn't show scrollbars and doesn't grow with

I want to show my own QWidget, created by QtDesigner in my MainWindow also created by QtDesigner. The MainWindow got a scrollarea with a scrollAreaWidgetContents layout. So, my scrollarea should display several instance of my own QWidget in it. The problem now is that my QWidgets are displayed but overlap eachother and the scrollarea doesn't show the scrollbars and doesn't grow with. I hope you can unterstand my problem and I know my english isn't the best :(.